public class Example3_6 {
   public static void main (String args[]) {
      double sum=0,item=1;
      int i=1,n=20;
      while(i<=n) {
         sum =sum+item;
         i=i+1;
         item = item*(1.0/i);
      }
      System.out.println("sum="+sum);
   }
}

